Whether grown commercially or in the wild, nuts such as black and English walnuts, hickory nuts, butternuts, and many others have an outer husk as harvested. After removal of the outer husk, a hard shell is revealed that protects the edible kernel or nutmeat located in the center of the nut. It is necessary to crack the hard shell in order to access the nutmeat, and furthermore, it is most often desirable to crack the hard shell in a fashion that prevents both the shell and the nutmeat from breaking into several small fragments that need to be painstakingly sorted. It is most desirable to crack the shell in such a manner that the shell is not difficult to separate or open and the nutmeat inside is essentially completely intact. Black walnuts in particular are considered difficult to crack without damaging the interior nutmeat, causing the English walnut to be the variety of choice for commercial production.
Many types of nut crackers are known and available on the market, ranging from familiar hand-held tools to semi- or fully-automated systems using anvils, plungers, or rotating cylinders and adjustable plates designed to perform the function of cracking nut shells and retrieving the edible nutmeats. It is usually important to prevent over-cracking the shell to avoid any substantial damage to the interior nutmeat, and allow retrieval of essentially a whole nutmeat. To accomplish this goal, it is important that the amount and location of the force used to crack the shell be applied in a fashion and appropriate amount that avoids, or at least minimizes, the transference of force to the interior nutmeat.
The following is a listing of United States patents that disclose various methods of nut cracking. The citation thereof is not an acknowledgement that any are prior art to the present invention, nor a statement that an exhaustive search has been completed.
Many attempts have been made to overcome the deficiencies found in nut cracking methods and apparatus of the prior art. The existing prior art has provided an invention relating to the shelling of nuts, particularly such nuts as coconuts, as described in U.S. Pat. No. 1,514,237 for METHOD AND APPARATUS FOR SHELLING NUTS, issued Nov. 4, 1924 to Tenney. The Tenney patent discloses a steam pre-treatment of coconuts or the like to facilitate easier separation of the meat from the coconut shell, followed by a clamping and rotational twisting of the bottom of the shell relative to the top of the shell using the mechanism described therein.
U.S. Pat. No. 3,561,513 for NUT-CRACKING MACHINE, issued Feb. 9, 1971 to Lindsey, discloses a nut cracking machine for the cracking of walnuts and the like that includes a container defining a compartment or reservoir for the receipt of nuts therewithin, conveyor means passing through such compartment for removing nuts one-by-one therefrom and for advancing the same in spaced apart succession into a cracking station, and nut-cracking means at such station and including both anvil structure and hammer structure aligned therewith.
U.S. Pat. No. 4,377,970 for NUT CRACKER issued Mar. 29, 1983 to Kenkel, discloses a nut cracker that includes a base that supports an adjustably fixed anvil member and a moveable ram member under the control of a handle, there being a guide interconnecting the ram member with the base which maintains the ram member in an erect position. The confronting faces of the anvil member and the ram member are provided with recesses into which the ends of the nut are received with clearance so that the outer rim of such recesses engage the nut to provide the cracking force to the shell remotely from the ends of the nut. With this construction, a heavy-duty unit is provided which is especially useful for cracking nuts that have hard or strong shells such as black walnuts and butternuts, and the construction further enables the shells to be broken and nut meats recovered in larger pieces without over-cracking.
U.S. Pat. No. 4,466,343 for AUTOMATIC ADJUSTING NUTCRACKER issued Aug. 21, 1984 to Thompson, discloses a nutcracker including a base, a stationary jaw, and an adjustable post. A driving cylinder is urged along the longitudinal axis of the post by a lever connected through a connecting link. A spring allows the post to float until a canting pin contacts one end of a ring disposed around the post. When the ring cants to contact the post, the force applied to the driving cylinder is translated directly to the post to crack a nut disposed between the stationary jaw and the moveable jaw.
U.S. Pat. No. 4,467,711 for METHOD AND APPARATUS FOR CRACKING NUTS issued Aug. 28, 1984 to Oiso et. al., discloses a nut cracking apparatus including a conveyor comprised of parallel slats connected to endless chains for intermittent movement from a hopper to a nut gripping and cracking apparatus. Each slat is provided with a row of openings extending therethrough for receiving nuts from the hopper and an underlying support is provided to retain the nuts in the openings until each slat is moved in sequence to a plurality of cracking apparatus. Each nut is located between an upper and lower nut gripping block each of which has a recess therein with a slot at the bottom thereof. The lower nut gripping block is spring biased on a fixed blade to normally have the blade retracted out of the recess. The upper nut gripping block is spring biased on an opposed blade which in turn connected to the piston of a hydraulically operated piston and cylinder device. Upon lowering of the upper blade toward the lower blade a nut is gripped between the upper and lower blocks and continued downward movement of the blade will cause the upper and lower blades to penetrate into the recesses to cut the shell of the nut into two pieces without damaging the kernel of the nut. Upon cutting of the shell into two pieces, the upper blade is retracted and the upper and lower nut gripping blocks are spring biased back to their normal position.
U.S. Pat. No. 4,665,814 for IMPACTING NUT CRACKER issued May 19, 1987 to Harborne et. al., discloses an impacting nut cracker which utilizes an impacting plunger activated by a compression spring or electrical solenoid to deliver a sharp blow to an aligned adjustable anvil to provide a stroke of measured distance to a nut confined against a tailstock anvil. A slidable and transparent guard cover over the impact area prevents excessive dispersion of the fragmented shell. A concavity in the tailstock anvil and in the adjustable anvil causes a circular edge to engage each end of the nut to cause circular fractures beneficial in achieving greater uniformity in the fracture pattern of the shell.
U.S. Pat. No. 4,787,307 for NUTCRACKER issued Nov. 29, 1988 to Rollband, discloses a nutcracker mounted on a base that grips a nut to be cracked between a moveable piston and an adjustable anvil. The user sets the optimum cracking distance initially by lining up an index marker located on the piston and adjusting the anvil to firmly hold the opposite end of the nut. Thereafter, the user need only move the lever handle to its up position and insert the nut—no further adjustment is necessary for similar size nuts. The user then moves the piston a limited distance by activating the lever handle connected to the piston through a toggle joint, or other limited movement arrangement. This limited movement enables the inventive nutcracker to crack the nutshell without damaging the meat inside.
U.S. Pat. No. 4,838,155 for NUTCRACKER APPARATUS issued Jun. 13, 1989 to Steffel, discloses a nutcracker apparatus that includes a frame on which there is provided a front and a rear head assembly that each has a head which is resiliently urged toward the other but is limited in such movement by a knife at least in part located in a slot in the head. Each knife is mounted on a rod, the rear rod being moveable toward the front rod to initially clamp the nut and as the movement of one head toward the other is limited by the uncracked nut, the rear knife continues to move toward the front knife to crack and/or split the nut.
U.S. Pat. No. 5,092,231 for NUT CRACKER issued Mar. 3, 1992 to Smith, discloses a nut cracker designed to accommodate virtually any size nut and provide the same degree of cracking stroke with the same mechanical advantage irrespective of nut size, with only a simple thumb-screw adjustment of a cam.
U.S. Pat. No. 6,209,448 for NUT CRACKING MACHINE issued Apr. 3, 2001 to Hagen, discloses a nut cracking machine that comprises a cylinder mounted in bearings for rotation n about a long axis of the cylinder. The cylinder has projections extending radially from its cylindrical surface. An anvil plate is held at a fixed predetermined distance from the cylinder when the machine is in operation. The cylinder is power driven. A feed hopper is provided for receiving nuts and directing the nuts onto the cylinder, the cylinder rotating in a direction to direct an upper part of the cylinder toward the anvil plate member, toward and increasingly restricted space between the cylinder and the anvil plate.
None of the patents, taken singly, or in any combination are seen to teach or suggest the novel method and apparatus for cracking the shells of walnuts or similar nuts, while minimizing the fracturing of the edible nutmeat within the nut.
The present invention represents a new and improved method of precisely opening hard shelled nuts while concomitantly preserving the nutmeat located therein. It is believed that such a method represents a significant advancement in the art.